Model Output Discussion - 15th April Onwards

[damianslaw]

Models all agree on a preety unsettled chilly outlook for the foreseeable future with the trough firmly locked in situ diving southeast across the country thanks to a very southerly tracking jet - this is territory we haven't been in since last summer. The prospects for a pattern change anytime soon remain very speculative at this stage. What is rather ominuous about the pattern is that it has the same hallmarks of the pattern we endured throughout most of our last 5 summers - a pattern which easily lasted upwards of 3 months... indeed recent years have produced lengthy spells of very similiar weather.. I wouldn't be surprised to see this pattern stick around for quite some time yet...

Next weekend could be a very wet windy affair.. most weekends this year so far have been preety decent for sunny dry weather, this one included.. Indeed I can't remember the last proper washout weekend (i.e. a wet saturday and sunday combined).

[Summer Sun]

Once more there is no spring warmth on offer tonight from ECM what is does offer though is more of the same with lots of low pressure systems over the UK

[Lewis]

Certainly a very very low pressure dominated spell coming up, can't beat a bit of low pressure, will bring much needed rain, and later on into the week we start to draw some energy and moisture from the SE/near continent, with the amount of instability to offer, we could see some nice slow moving heavy showers, and of course thunderstorms

Could be a good week quite widely for some storm chasing.

[legritter]

evening all ,i havent posted in here for a while  but i do read frequently the pists .and posts . sorry but didnt have my glasses on .certainly looking like the next  two weeks will be low pressure dominated .plenty of interesting weather to come . all that arctic air trickling in our direction .its a shame we werent  two months back .looking at all the charts it gives me hope that if you wait long enough anything can happen , so please keep posting, all those regular posters who do all the research  ,i say a big  thank you ,heres to the best forum  in the northern hemisphere ,CHEERS  LEGRITTER .

[Aaron]

Absolutely no chance.

-6C in mid-April under the conditions we're experiencing today? I bet my house on it that -6C will not be achieved away from the Cumbrian frost hollows, and even that's a push.

Far too much cloud around away from N.Wales looking at the satellite imagery, and there's a breeze starting to pick up too, rather windy on the Eastern side of the country, coasts especially.

I'd be surprised if -3C is reached tonight. NAE looks bang on. -1C/-2C your typical low in sheltered areas.

Hitting Ctrl also clears the cache. A standard F5 just refreshes the page..

-3C was achieved in a few laces this morning, such as Benson and Shap and -1C here, a non frost hollow location. Why are people so quick to rubbish everything? -6C in April is hardly unusual.

Edited April 15, 2012 by Aaron

[coldwinter]

This is interesting, the trough moves to the west/south west of the UK, this, as mentioned by others could give a warm and potentially thundery spell, NAEFS also trending this way.

Ryan

[johnholmes]

re the comments about the possible lowest tonight, clear skies for many, lower gradient strength=less surface wind than last night for a large part of England and Wales; last night several low level places got -3C, so I cannot see why the -5C is not possible and possibly for more than 1 place?

we shall see come tomorrow morning.

I'll do something unusual and stick my neck out!

-6 or perhaps -7C somewhere in England and Wales and NOT a high level station, ie Gt Dun Fell etc

Edited April 15, 2012 by johnholmes

[peterf]

certainly colder than this time last night which bottomed out -2c at 4.40am.

currently 0.7c with a drop rate of -1.7c /hr.

[bluearmy]

This is interesting, the trough moves to the west/south west of the UK, this, as mentioned by others could give a warm and potentially thundery spell, NAEFS also trending this way.

Ryan

Naefs certainly should be trending this way as that chart is generated automatically from naefs raw output at the weekend !!!!

[4wd]

In the calmer conditions tonight it will be coldest in some valley bottom like Topcliffe.

It's below -1 here already, and I'm up a hill. Probably a bit of breeze will stop it falling more soon here.

[coldwinter]

Naefs certainly should be trending this way as that chart is generated automatically from naefs raw output at the weekend !!!!

Sorry my bad, but i bet it will look similar on Monday, i forget that it is generated from NAEFS at weekends.

Ryan.

[Glacier Point]

This is interesting, the trough moves to the west/south west of the UK, this, as mentioned by others could give a warm and potentially thundery spell, NAEFS also trending this way.

Ryan

Not sure how warm that would be..you need the mean ridge to our west to alter its position somewhat.

GFS ensemble mean H5 and 850 T anomalies for days 6-10 and 11-15 suggest unsettled (very unsettled first week) and cool becoming average, the warmth to our east:

The dynamical processes in the atmosphere have rather stuck themselves in the current wavelength, and no signal for significant change in the forseeable timeframe from my perspective. Unsettled with showers or longer spells of rain, below average temperatures through day 10, thereafter something of a recovery to average or possibly a shade above but remaining unsettled with mean trough solution for the UK and -NAO / neutral - negative AO regime.

Edited April 15, 2012 by Glacier Point

[coldwinter]

Not sure how warm that would be..you need the mean ridge to our west to alter its position somewhat.

GFS ensemble mean H5 and 850 T anomalies for days 6-10 and 11-15 suggest unsettled (very unsettled first week) and cool becoming average, the warmth to our east:

The dynamical processes in the atmosphere have rather stuck themselves in the current wavelength, and no signal for significant change in the forseeable timeframe from my perspective. Unsettled with showers or longer spells of rain, below average temperatures through day 10, thereafter something of a recovery to average or possibly a shade above but remaining unsettled with mean trough solution for the UK and -NAO / neutral - negative AO regime.

Yes, a continuation of the unsettled theme looks very likely in the forseeable but temperatures perhaps edging above average at times though, with troughing close to the UK, whether the trough can edge west and pressure can build over europe we don't know, but certainly a contination of the unsettled theme.

Ryan.

[johnholmes]

re the comments about the possible lowest tonight, clear skies for many, lower gradient strength=less surface wind than last night for a large part of England and Wales; last night several low level places got -3C, so I cannot see why the -5C is not possible and possibly for more than 1 place?

we shall see come tomorrow morning.

I'll do something unusual and stick my neck out!

-6 or perhaps -7C somewhere in England and Wales and NOT a high level station, ie Gt Dun Fell etc

and once again old man weather makes a fool of me, at least to some extent, -5C I've seen at one place but take a look at the sat picc for the chunk of cloud that has come off the N Sea for many NE and E'ern parts of the northern half of England.

[Polar Maritime]

Yes JH not as low as i thought, dam cloud.

[Summer Sun]

GFS 00z remains unsettled to the the 27th and then high pressure has a go at building from the East for a time

ECM is also unsettled for its run to the 26th but it also shows high pressure building quite strongly to our east

[Scorcher]

GFS 00z remains unsettled to the the 27th and then high pressure has a go at building from the East for a time

http://www.jp2webdes...o.uk/ds/gfs.htm

ECM is also unsettled for its run to the 26th but it also shows high pressure building quite strongly to our east

http://www.jp2webdes...o.uk/ds/ecm.htm

Remaining unsettled yes but hints of warmer air moving in from the continent around the time you mention on both GFS and ECM.

[Summer Sun]

GFS 06z follows on from the 00z with high pressure to our east bringing in some warm air from the continent

Changes could be coming as we move into May

Edited April 16, 2012 by Gavin D

[Lewis]

GFS 06z follows on from the 00z with high pressure to our east bringing in some warm air from the continent

Changes could be coming as we move into May

Blimey them sort of temperatures and weather pattern feels a long way off, I hope the above charts you posted come in to fruition, but we need to get through an extremely unsettled period this week and possible early next week.

Gale force winds, driving rain, heavy showers, embedded thunderstorms, a very active spell of weather to come.

Edited April 16, 2012 by UK Storm Chasers

[Alex]

Little changes on the models this morning with a trough fully anchored to the UK, however as we head into the latter stages of April, there are some hints that the trough will push slowly westwards which allows us to be on the warmer side of the trough. The GFS 06z picks this out nicely and this has been a clear hint recently on other runs.

I just wonder whether we can push that continental high more west with time to give May a warm settled start?

[bluearmy]

Not sure how warm that would be..you need the mean ridge to our west to alter its position somewhat.

GFS ensemble mean H5 and 850 T anomalies for days 6-10 and 11-15 suggest unsettled (very unsettled first week) and cool becoming average, the warmth to our east:

The dynamical processes in the atmosphere have rather stuck themselves in the current wavelength, and no signal for significant change in the forseeable timeframe from my perspective. Unsettled with showers or longer spells of rain, below average temperatures through day 10, thereafter something of a recovery to average or possibly a shade above but remaining unsettled with mean trough solution for the UK and -NAO / neutral - negative AO regime.

sort of agree stewart but the trend, day by day is too edge the trough a bit further west (more so south west) post day 10 and for the heights to rise to the north and east. a neg NAO is the obvious solution but maybe a more west based one will allow a milder flow across parts of the uk. i have been following this for nearly a week now and its a become a fairly consistent trend for the euro heights to rise whilst the trough drifts west. it wouldnt take too much more of a shift west to leave us in a warm continental flow.

[johnholmes]

I can see both posts as being correct if that makes sense.

I think its possibly too soon ba to seem (note I say 'seem') ba to be as beieiving as you appear to be about the trend and its end result. I agree the trend is there but I would want to see this, from all 3 ouputs I use, over another 3-4 days before I would start to think that a pattern change is under way.

I perhaps err more towards GP's version at the moment but see my comments in the above paragraph.

3-4 more days of the same trend happening, especially if the upper pattern way west over N America and the Pacific appears to be showing a change, then it would be time to suggest a change is on its way. Not before early May at the earliest is my estimation at the moment?

Edited April 16, 2012 by johnholmes

[Summer Sun]

GFS 12z remains on course to bring changes as we move to May with high pressure building strongly to our east before moving over the UK as we enter May, although the warmth GFS was showing this morning has gone the high pressure to our east hasn't

UKMO is unsettled for all its run

[AWD]

GFS 12z remains on course to bring changes as we move to May with high pressure building strongly to our east before moving over the UK as we enter May, although the warmth GFS was showing this morning has gone the high pressure to our east hasn't

http://www.null/ds/gfs.htm

UKMO is unsettled for all its run

http://www.null/ds/ukmo.htm

Mmmmmm, not as settled as previous runs suggested! Disturbances in the flow remain right out until until T384 generally speaking! All along way off yet anyway, but HP to our east remains a good shot as we enter May, just a case of how far west it gets to affect our weather! I'm not so sure a domineering HP will set up over us in early May, but more of a HP influence from the East, leaving much of the North and North West under an Atlantic influence still, as Atlantic systems travel NE over Scotland, much like the Met Office long range forecast suggests!

Unsettled and often wet/showery with rain for all for the next 10 days, remain on the cool side of average, things turning less unsettled after that from the south and east, but still with a reduced shower risk, temps recovering to average and then to slightly above average, continuing unsettled further

north and west, with LP systems bringing rain and wind at times, temps remaining average at best, at times below average!

[Lewis]

GFS 12z remains on course to bring changes as we move to May with high pressure building strongly to our east before moving over the UK as we enter May, although the warmth GFS was showing this morning has gone the high pressure to our east hasn't

UKMO is unsettled for all its run

Dear mother nature,

Would you please hurry up high pressure establishing it's self across the U.K, for Gavin's sake

Thank you

lol